题目内容：

Flying is a fast way to travel. But it is a big headache for some people. They can’t help worrying about things like, “Is turbulence (颠簸) a bad thing?” or, “Is it dangerous if we don’t change our mobile phones to flight mode (飞行模式)?” British newspaper Daily Mail spoke to some experts to answer these questions. They also tell us other interesting things about flying.

Is turbulence dangerous?

It’s scary and uncomfortable. But it is not something you really need to worry about.

Turbulence is caused when two groups of air hit one another at different speeds. Wind, thunderstorms (暴风雨) and being close to mountains can be reasons for this.

You may feel like turbulence is dangerous, but it won’t crash (坠毁) your plane. “Even in extremely rough air (扰动气流), the wings (机翼) are not going to break off,” explained Patrick Smith, an airline pilot, who is also an air travel blogger and author of AskThePilot.com.

Why are plane windows round?

Round windows are for passenger safety.

As the airplane flies higher and higher, the outside atmospheric pressure (气压) gets lower and lower. During the flight, the pressure inside the plane becomes greater than the pressure outside.

When this happens, square windows can break. That’s because having different pressures inside and outside puts pressure on the corners of square windows. But rounded corners can spread the pressure through the window.

What happens when a phone isn’t on flight mode?

Some passengers believe mobile phones and tablets need to be turned off because they could bring the plane down. However, this is not true.

If you don’t change your phone to flight mode, pilots and air traffic controllers may hear unpleasant sounds in their headphones. It also influences radio communications. So it’s still best to put it on flight mode.

1.According to Paragraph 1, we learn that the story is going to _____.

A. show what worries people may have about flying

B. interview some experts about flying

C. give people tips about how to travel by plane

D. explain some interesting facts about flying

2.What will happen when there is turbulence?

A. People may feel uncomfortable.

B. Two planes may hit each other easily.

C. It will make the plane drop suddenly.

D. It can break off the plane wings.

3.Planes use round windows rather than square ones, because ____.

A. round windows can spread the pressure

B. round windows can add outside pressure

C. square windows can lower(降低) the pressure on the windows

D. the corners of square windows are difficult to make

4.What happens if a phone isn’t on flight mode?

A. The plane will crash.

B. Air traffic controllers can’t get any information.

C. It may influence radio communications.

D. It may be noisy in the plane.

5.The passage may be taken from _______.

A. A story book   B. A science magazine

C. A guide travel  D. A novel